	/* layout */
    div#app{
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        width: 1280px;
        margin: 0 auto;
    }
     
    @media screen and (max-width: 1024px){
        div#app{
            width: 100vw;
        }
    }
     
    header{
        flex: auto;
        min-width: 100%;
        display: flex;
        align-items: center;
        justify-content: space-between;
        height: 100px;
    }
     
    nav{
        flex: auto;
        min-width: 100%;
        display: flex;
        justify-content: flex-start;
        align-items: center;
        height: 40px;
        background-color: #003388;
    }
     
    main{
        flex: auto;
        min-width: 100%;
        min-height: calc(100vh - 140px);
    }
     
    footer{
        flex: auto;
        min-width: 100%;
        height: 80px;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        background-color: #e3e3e3;
    }
     
    a{
        text-decoration: none;
    }
     
    img{
        width: 100%;
    }
    